Measurement of charged particle $R_{AA}$ at high $p_T$ in PbPb collisions at $\sqrt{s_{NN}}=2.76$ TeV with CMS

Charged particle transverse momentum (p_T) spectra have been measured by CMS for pp and PbPb collisions at the same s_N_N=2.76 TeV collision energy per nucleon pairs. Calorimeter-based jet triggers are employed to enhance the statistical reach of the high-p_T measurements. The nuclear modification factor (R_A_A) is obtained in bins of collision centrality for the PbPb data sample dividing by the measured pp reference spectrum. In the range p_T=5 - 10 GeV/c, the charged particle yield in the most central PbPb collisions is suppressed by up to a factor of 7. At higher p_T, this suppression is significantly reduced, approaching a factor of 2 for particles with p_T=40 - 100 GeV/c.

Note:

Proceedings of the talk was given at Hard Probes 2012, 27 May - 1 June, Cagliari, Italy

Nuclear modification factor
particle suppression
CMS
LHC
charged particle: transverse momentum
charged particle: yield
nucleon: pair
jet: trigger
suppression
CMS

References(7)

Figures(3)

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Measurement of charged particle RAAR_{AA}RAA​ at high pTp_TpT​ in PbPb collisions at sNN=2.76\sqrt{s_{NN}}=2.76sNN​​=2.76 TeV with CMS

Citations per year

Jet quenching

Importance of correlations and fluctuations on the initial source eccentricity in high-energy nucleus-nucleus collisions

The CMS Experiment at the CERN LHC

Study of High-pT Charged Particle Suppression in PbPb Compared to pppppp Collisions at sNN=2.76\sqrt{s_{NN}}=2.76sNN​​=2.76 TeV

Charged particle transverse momentum spectra in pppppp collisions at s=0.9\sqrt{s} = 0.9s​=0.9 and 7 TeV

PYTHIA 6.4 Physics and Manual